Wardle in the hot seat

It's not just the soaring temperatures that have put Robert Wardle, head of the Serious Fraud Office, in the hot seat. The SFO has fought two high-profile cases since Wardle took over in February - and lost them both.

In July, Les Rosenthal, former buying manager of Wickes Building Supplies, walked free after being accused of a £20 million fraud. Then last week Andrew Regan escaped a stint open prison, having beaten allegations of theft from his food company, Hobson. The 'Serious Farce Office' tag surfaced yet again.

And Wardle, as case handler for the Regan prosecution for almost three years, took a lot of the flak personally. Some of the criticism may be misguided. The Regan case was set in motion six years ago, after Regan's abortive attempt to take over the Co-op. The first case officer was Fred Coford, who led the Regan team until October 2000. After Coford left the SFO to join a firm of private investigators, Wardle took over.

Coford left Wardle with a weak case. Wardle wanted to extradite Regan on charges of corruption. But Monaco - where Regan lives - does not recognise the charge of corruption. So the SFO decided to extradite Regan for theft. In the summer of 2001 Regan finally appeared in court. But the jury failed to reach a verdict.

The next trial, in January 2002, was stopped after four days, after an apparent attempt to bribe the jury. One of them reported that one evening he opened his front door to be greeted by a youth with a mobile phone. At the other end, the juror said, there was a voice telling him that Regan was innocent and that he would receive £10,000 if he was acquitted. At the third trial a similar attempt to 'nobble' the jury was suspected. There were various theories about who might have been behind these alleged approaches, but the jurors now had 24-hour police protection.

The SFO had other problems. His main witness was Ronald Zimet, a mysterious Dutch-Israeli businessman, one of the richest men in the Netherlands. The former Ajax goalkeeper had made his fortune after he sold his Japanese investment company, Pacific Basin Securities. But he had also acted as the conduit for the £2.4m passed from Regan to the two Co-op directors who had given Regan's company Hobson the supply contract. Zimet was secure in Israel and, not surprisingly, unwilling to come to the UK with the prospect of a jail term. So the SFO offered him immunity from prosecution in return for his co-operation as a witness.

But legal immunity was no protection against Regan's lawyers: 'It is an affront to consider Ronald Zimet anything other than the most tainted, the most unreliable witness,' said John Kelsey-Fry QC, defending. The jury was unconvinced by Zimet. And Regan's lawyer found the biggest flaw in the SFO case: he asked how Regan could have stolen from Hobson if his actions had helped boost the company's share price? Also the £2.4m had been withdrawn from the Hobson bank accounts with the support of the finance director. The jury acquitted Regan by a majority of 10 to one.

But fraud experts are not calling for Wardle's head. Some argue the SFO has become more efficient. 'They seem to have got better at choosing the cases they fight - they leave cases that they might have unwisely taken on 15 years ago,' says one City fraud lawyer. But the defeat could push the Financial Services Authority to encroach on SFO territory. FSA insiders feel the authority is better placed to stop fraud in the City. It can force witnesses to talk, has more resources than the SFO, and can apply sanctions - either huge fines or banning from the City - without going through a trial.